Sunday, April 2, 2017

Streetcar test track and the search for a happy minimum

I was reading on wikipedia that the TTC streetcar system has a minimum turn radius of 36', which translates into about a 5" radius curve in HO scale. My previous layout had minimum 15" radius curves; far too large for a convincing representation of the street. I laid down a lumpy loop of track - almost an oval at one end - of 5" radius to run some tests with my fleet.
It turned out only one end was more-or-less circular and the other was a bit too oval, but it worked out to be a fairly ok 5" radius test track. Only the Bachmann Birney single truck tram could handle that tight curve. None of the PCCs could.
I was crazy when I built that loop. I figured on all members of the fleet successfully negotiating the 5" radius curve. I got a little smarter when I had to do tests with 6" and 7" radius turns. I drew a guide on my cork board and temporarily thumbtacked down a strip of track. It turned out to be a good approach: a 6" radius curve was also too tight, but 7" worked just fine. To be a little more specific: the Bachmann Peter Witt could handle a 6" radius curve, but the Bowser and Con-Cor PCCs couldn't, although they could handle a 7" radius turn. It looks like 7" will be the minimum radius for curves on the new layout.

2 comments:

  1. This is useful, helpful stuff. What sort of flex track are you using? I know Atlas has really easy-to-flex track, but other brands do not flex as easily without coaxing (and sometimes swearing).

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    1. Thanks! I used Atlas flex track for both this HO scale test setup and the N-scale one I posted about earlier. But, for the N-scale EVRR layout I'm planning to use Peco. I like their switches and I've bought the ones I need. I've also got a few lengths of Peco flex. It seems a little stiffer than the Atlas, but I haven't worked with it enough to know for sure.

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